378 



MODIFIED CIRCUMNUTATION. 



CHAP. VII. 



stick, and the movements of two leaves were traced on a vertical 

 glass during 72 h. The plants were still kept in the dark, ex- 

 cepting that at each observation, which lasted 3 or 4 minutes, 



Fig. 158. 



Mimosa pudica: circumnutation and nyctitropic movement of a leaflet 

 (with pinna secured), traced on a vertical glass, from 8 A.M. Sept. 14th 

 to 9 A.M. 16th. 



they were illuminated by two candles. On the third day the 

 leaflets still exhibited a vestige of sensitiveness when forcibly 

 pressed, but in the evening they showed no signs of sleep. 

 Nevertheless, their petioles continued to circumnutate distinctly, 



